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C . <br /> drinking water standards. A replacement well (DW-1R) for DW-I was constructed in February 2004 <br /> -- and put in service sometime between July 7 and 11, 2004 for the domestic water supply to the Ranch <br /> Market. Well DW-1 has been disconnected and is inactive. In accordance with a letter from San <br /> Joaquin County Environmental Health Department(SJCEHD) dated February 26, 2004, sampling of <br /> well DW-1 has ceased. <br /> 2.5 Free Product <br /> Free product was observed�in groundwater monitoring well MW-3 during the First Quarter 2004 <br /> sampling event in January 2004. Upon discovery of.the free product, Geocon began frequent <br /> monitoring of the product level and bailing to remove it. Measured product thickness 'ranged from an <br /> initial maximum of 0.5 foot on January % 2004 to 0.012 foot on February 9, 2004. <br /> On January 30, 2004, Geocon purged well MW-3 in an attempt to create a cone of depression and <br /> draw additional product into the well. No increase in free product thickness was noted from the <br /> pumping effort. As of February 9, 2004 approximately one-half gallon of product had been removed <br /> from MW-3. The product odor, color, and apparent viscosity are consistent with weathered gasoline. <br /> Eli <br /> Based on the presence of free product in well MW-3, SJCEHD requested a written summary of the <br /> findings and proposed actions. Geocon prepared a letter..regarding Free.Product Discovery and <br /> Proposed Actions, dated February 18, 2004. Geocon proposed to continue monitoring and to remove <br /> free product. <br /> USTs were removed from the Site in 1991, and the Site has not operated as a fueling facility since <br /> the time of removal. In more than five years of groundwater monitoring and approximately 1.5 years <br /> of remedial activityat the Site (1998-2004), free product had not been encountered until the First <br /> Quarter 2004. The discovery of free product after a significant period of time of source removal and <br /> i remedial activity could be indicative of an additional UST at the Site.Accordingly,Geocon proposed <br /> to perform a records review at SJCEHD and perform a geophysical investigation at the Site to <br /> evaluate the existence of additional UST(s). In a letter dated February 26, 2004, SJCEHD conc6rred <br /> with Geocon's recommendations. The findings of Geocon's proposed actions are.discussed in this <br /> report. <br /> �y <br /> i <br /> t <br /> r Project No.56643-06-01 4- December 30,2004 <br />